SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df240c13e169b918af45e42285ba3f6f697374162655fffafd0efdfd8612261f' 
  AND token = 'xmxLq1bt5ERrIHU6YPC69oOFg0taaoKUCKiXgziRt2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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