SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985d31b92a0bf288df14fe38f967abea8e0dfdb18df903b84e5d1318cc28dd7b' 
  AND token = 'rSDt2d0/7oHwRhScvkZP+kqwz1VItkLfB0gdgtTzdoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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