SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a80edffa141699a572e92c257d738e1861c077128ba30fdeffa73da56ba7da51' 
  AND token = 'raUls7Oue+E+FCInh5CqU7M1zLfmeZiIreKSeC5aT5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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