SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2185b5c5d59b07284d92863a654d276f31283a1b2e845d297c381d1a64accf2f' 
  AND token = 'D5lIuyPGMiSqVxj5vtF8s6xVhyGbLyG10/PKK9iGO+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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