SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdd4085e88549d43b04ed549da98492516d85d650076ce2310e0aaa251749e69' 
  AND token = 'w/uMTpFwbt4MUooj09dTszMTDi6Q51bWpfuKKUWXe78=' 
  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"
    }
  }
}