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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '556cab85e8db44cc1843c4cb53a0cbaddb2790280487f9a010021c590323ee21' 
  AND token = 'udQyeyONaK3JD6c2lZLekQENtdLSqmd0tijlWMk7s74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}