SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fd7639ba81fe19a5e9bba321848f2265decdeeb44b424933e0609ca82c8110d' 
  AND token = 'N2Oh4tzVjNk9LyUfxQcNOPI3oNq8LZp66TxJbbNZXlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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