SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd54d3e85dbdd6ed0a83f707e5d2c54c2ee3014b363b16c91e93090349389d1b' 
  AND token = 'DfjNAlIPFd3Gnafn+E4uBcsehkmUqqNav7Fs+Wxs+lw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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