SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf8ce302e06a3ff078034327df82b1bc1f3a4e1d5f5a7c4db62c2abb30369b61' 
  AND token = '4TKbOLZhGUXEZd7vluORJgV+WhpH7r4hvMtQy0tcf/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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