SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ffca602d4df90af7b1398ce135ddcaafc60a6023a5ae9163d144bb7a6f320dd' 
  AND token = 'fw2MmxYfPM6HSK46xSg+lqkORI1gYJC9soyr7jKmdPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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