SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd12f79853a8bdb2635ffb37829340995195adf266dac6e76967f47e8129b24f2' 
  AND token = 'RAsZzd68lp4ICdm+4K2GvcEaqLnqNFgYM6+xmv8n1Fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}