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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8b5991347d8d0ef94cb27c0dd3e9e8d5c352a47155929f6599c9d2ce2b304e3' 
  AND token = 'MlQwvHH/q1Jp+ymBWG3osHOqdRLi5dDargyF6d9yN0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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