SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd38c7c46b24f21bdc43a5f5146824bbc6684b6eb061709fffd4401f25203907e' 
  AND token = 'gMz40BIgAJxRhSl+TrgrXaepzOywaGOuTPcdqHBKAAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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