SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '381949312b7f42621a88bcfcc06b61943610b91be56c60e610a061df70283293' 
  AND token = 'LAZV78lrc6yd/bDaB4+MPpzlV4YO80diD1ejCzcMCDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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