SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3425cef4149bfb689df3cff7f3de2d2b692796fdb18a246ee03a9a391c2ad375' 
  AND token = 'phKhacIYtROJYI4uwi2U7wLUZ+0BUusoC3q4EqAi/+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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