SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c902c99f51611331cd389a7657faf3026c120294fabb52e70b6b45f10a94984' 
  AND token = 'GsplnStkCr651c4iR6W7PletMZqKviBWMHuHDvsH2MA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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