SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4b5db9f9d4b23cafb247628d6dd616a7a6a95b31a145fefd39619363b396a416' 
  AND token = 'FTC/S3Ix2tDSkyHpS+A8tZJ6cAZRQR8xgJQJRgxYKDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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