SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c526fc34f1549bb66540cd36732fd11e448faeaaef157236bd581ab08025791c' 
  AND token = 'E/FnHzBmKpC1UZRoG/TO/8qZ4fY7TXlSI3+U5eGAI4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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