SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db517e731fb00568159f1813b864c4c31be0875fb6e4f21a49ac185773091384' 
  AND token = 'Nw8dzW+uAnprx4iYsP4exD1N2VU3PBLIkWiAzxwOQ+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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