SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c058c8bf227f636cb86fed1267fda1d9e1a8615fdf6da60ec6b6448ab575982' 
  AND token = 'V+U/F2qCNNF5Bvv0RWIdgB5W4Nr2Ia5UifjWP03k548=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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