SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d613d307585419e7accc455aecb45d1629d4c4d1d72f9cfb6330f217027db36' 
  AND token = 'ZEHF7fM5h96lZCShgYFnD8nvYuTkwzK92fFJaBeVguA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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