SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '283059b69f780424aec0be822a2f20cfc76c67a154271b87065926f3dbba74de' 
  AND token = 'rYumj6vxNoNXXOycFydDO6LVsbLLw2UFtgQ8mTxOnTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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