SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ebc742376a268a88eb20c2190266280647c2571b670fdf6e7024c10858ec5df' 
  AND token = 'aYIsFhX8UExNCTto6D0gxSAalFAmC2owzps20phNpDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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