SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86bcf68d3326af21590cd680dc936d64373071d187dcde481571d87a25517d9a' 
  AND token = 'PjsR+2bTZ2tSfY2PUOXOGLf9QvCoE47WchtIws/Xpak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}