SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35f97ef8c7019c07bfc88909a0cff3bb06b3842bb23d47a7b06add9fae1f0839' 
  AND token = 'WzpINWZxOgrKJ1WKRIW7mTRCEeLZxVha5RS8ngmYAMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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