SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b2c315add018e06c5e8a6323549797dc3f6bdd164c63be5a8ef3bbd0ed49151' 
  AND token = 'gy0LK+IDhHVyN6z6Ht/WZOmj6uf+P/u4bdbNmb5ymJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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