SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9f300d2d4bcca77c45e89a3617b1c0395cfb2408fc07a9d9583a764575850783' 
  AND token = 'Xmzqe395L4zVBC5JRju/r48TzH/+6WM3Ut1Hde2fQFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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