SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c2e6b0030ca6ebfbfbbe0282aec24b9aee7be21cba50eb840efffe45e459208' 
  AND token = 'UzEGN+u6JPlCtt8mMsKp7v1H1HMOYzPtdfmuwbpJc+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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