SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f890b8ec24a5fc13c29cd57ee74bf0aa33fbe568e4b43eefd13b6c493ba55cec' 
  AND token = 'qRsTL+MIJLr99ZlrAUwLYGzcsgBQCcR++LD/qGSg9DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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