SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aefe73fd8473ff3d9d300a5a30e00123b2cc936637f79f7b6699777a12e4e172' 
  AND token = 'ffI/Xb9LgmROwprG3xng7xeej7Tkrq5bv4lMeeTf2zY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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