SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37f64e132fac110e67a796e73b68688b0df95aa1f5c9ea4a823e15b151020271' 
  AND token = 'oZJcuY7C951sJRzfqMGwtEXwoTvDjZ1mmRVxvqhD9Go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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