SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59c552c700066540e914dd5afaf770a43d6d68d805679a494e94d470f7c711ec' 
  AND token = 'HtO+9v9MFAiNCvlQ+mIzq6CfnfMTJRz5HV1Bt0WLQi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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