SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebf3b6d1bf2cc7bcf9fa15c67773b4da01f23269274e69961b3665b3650dc31e' 
  AND token = 'xkO58HdSG3/PgMgLWHBJMlL4XMpH8QO6aq8K056Eb6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}