SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8dddcb74a4ea106d251d20305e7eec41e1f4aa65c96d6824dfe19a98076f61b' 
  AND token = 'cI8dTPjIt2i2kE2XryvctAqNe0W/3Fcc73CvNsCDF1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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