SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c023d1c51cb0faacf6df8fd109f253e9ab1ba21229e7bc503773f40ba94cbab5' 
  AND token = 'vdeeVmwmDncN4xz58xtrNjSpojUOv+LlfR4sk1JBOJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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