SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75efdf5973bf53cf3180652882f766ee79cadda162acb5a4d199a4b26143a9da' 
  AND token = 'Y2ytD+L9iJRAv1P0qjWvjyufm1FHp20/PaAzFq61gxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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