SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a11d0fad5d340bab5e71b1bb33a317f47e95c92f0ecbfae22e960a27d2448c9' 
  AND token = '6YEFInUxczBRHilqQuqt1paeocpFtEfPdosyKpbYovs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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