SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '392a27a95165edd4180196785d7507257dbaec60772b36fd630ef1da72cdcd6b' 
  AND token = 'rvDQIlxRLk4jJUtxcLDdqHq0ghOnvCznd0Hgyij/mbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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