SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e114c2d761e370e168d740df44b018dbe6c6461ed1f353e51c980dd3f871ebc' 
  AND token = 'iRQRBxqF+fODRmRo7aM3wmN9gvnIRFEsoWkxWpmgUqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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