SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48036fe4c8a1bb95d9ec1712876a883b2a5a5372195b58cb52d78fdaf9ac05e7' 
  AND token = 'Up54FTU4limFibnLrMlz/afRKaBs+Ch9+IvgTX1IpU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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