SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30a9bbb31096f026f9e61bb6d8dfb0da2d4b05177826d8d9aee82970aed34de' 
  AND token = '6JSyGRI1tnhOH11iPWyGk4iuyIqYUQTKe29v05YxT/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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