SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9fa12e7fe1dd9faea923bad505677f0aa3801a71864693a91129f4fbe6a9216' 
  AND token = 'i2jB87nwcJs0CUCnPJMqMdZectz0DMlATqaNfzCLFwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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