SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '10fd39a7c90916ec85c136d1cc5c9c33c771dfa41d986b520069ccf246ff0353' 
  AND token = 'j5cmoDsIdcwj3bnqLzVL85B5UFVb0C6nAMMvlzzvgag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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