SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e7b49026eec877dcfd26d909834d29e81fe70ef545ca9626b4221537e788372' 
  AND token = '8wg3h33wKxDY1CDVFLJj8CuS6VXQeYktBLjDlREywqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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