SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3808b6198bfa11fa95c3e70bef5d5199c56f53602c624331f528c1ff6c12cf9e' 
  AND token = '5jO2IXNwrAeR7Mt2eBUZGyzvEsOBmLSGRj5atVDeHjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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