SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c66f5545922c4f7f95546c35d0b762b7c3d00cb204a4c8db73d6eca39342640' 
  AND token = 'fSKuJX5uhhWDrVGoR2kYqLUoAzQjD+C9D81nqfHwJUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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