SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0413eb6eff0d52210ad288783913802137509c042cf758cf93420529ffa1ec5' 
  AND token = 'rD8ewgdhhjuUMzLPRaJT+GD/HkPfXWbQLUUVIAHdJ7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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