SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99c71bc355ab78152e4eed02b19a8c3a93b9e11ef785db1453d8e9bef6095924' 
  AND token = '9COJAx1z45lifPljiDQIe2OWdJT8c6yqz59EDPbue0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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