SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b918ac1c59ed456a66f41869adc4069bb3e6e71ac57e2a4a92c2813ecf286dc5' 
  AND token = 'hQiSlOkvlGZHcyVhJZzKg1XkEIsssqlv/bp6sECDrxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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