SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7303698148916b3ecd336fbc0ed9183f5f62b8b4590a32455c789fb60320cd1' 
  AND token = 'aHXfSw2K4Z7xXZDCNys7UiGjNkskCX0pB/aKG1VngCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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