SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '710b7306fcd650f0b6d07691a4cba2b3776d8cec5dfb6bb97e1a1272607ee455' 
  AND token = 'R97rvXzvYUfc03btxkNOBcJP3Ygu+zJGqUHIynOMGOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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