SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7313395646343df8236f58ccedd67dbfac9d93336564b0e7df695d13ba241258' 
  AND token = 'Audf2juWk+v8tFYztJV1Snl1ZytVgYV04MurBCXv3RA=' 
  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"
    }
  }
}