SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4e8d5166c021bfea6af209abcd892122162ca9240398a1e3c0c01b409620651d' 
  AND token = 'asCvSIbzb/rcCvszQL5n7WHt1eiwahAb65cHuEw0b1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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