SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '245059f7fb7806070e797127173d78e8ce394d008b0fd3102fa044643ddde89c' 
  AND token = '66pRMy9FTZc+yL3yzQm5N3wqrVBBEK8Hn/rIjvFYIoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}