SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c19f90e5ea3e8a8fccaa496dc2a389a49925903aadff6a99eaf3ce672c456ad' 
  AND token = 'yknObLFXHI2nehvvjkWGx1qXqO58fuHthIZqHJnAfiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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