SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '984818ddbb518a35b62fdfffb42e50e63d83d3789327f1c72bff39faa938b31f' 
  AND token = 'UkREL0HVz8K/E/mETUh44+ZPCzbGCiD46/Lr+VYoYMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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