SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a1d38763934cdb2e69de44d2c3cafdccc4c6178f84e679869b44c463c7bf716' 
  AND token = '7aRXVdw7OVBHeI2Jhx0t28TtOY2iIloO8o2AuXevc3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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