SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0867a027a532bfbd3274741565b67865b12886cabf364e7d207fb2cdc21eb555' 
  AND token = 'rLo71Lrcg07iAZNdZ05ZJyAM95FeXPIukY4omurkYBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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