SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc5766097c243ee17c9a233e64b6a458c5d7054a393503edd6b7ec560fe1aa4e' 
  AND token = '/jmhiIWFQRfNVFTWEsE+h/N5QBnbpPgAjWbBDGRYgrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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