SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd6a66101b7a1ede2e5483911987ec75765e6cc6fdc301e88c588996beeba0b' 
  AND token = 'ilzkqAZRI7304iV2D4VYcWiVZIBrTAn+k4cPVxBu990=' 
  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"
    }
  }
}