SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8a5e3bc7dd97e150dca41715446b34b970044b6ce9d422bb2fc1afafd9330f8c' 
  AND token = 'Mq9GjmzpAQqbpw2fmPEmYwJyw17D2E85UZb/7eIhQ7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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