SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b1d2a85ec994443411852d5f82aa5f350f9c4578e0b80974deff8239bc6564' 
  AND token = '9u30Oky/W+8ZSHPlBxmhRbD19ZGmEs1esfzgcUqh/6U=' 
  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"
    }
  }
}