SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b2093ff40a2edb4cf8f58bc1252b61896c17f9e2c278d4b24bfa068193a6c54' 
  AND token = 'dbtMqvCuGRAjSMSFsstSaNZxigiuogEkPmG1UlxAne8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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