SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '25ccc6d4a5426e0204e6aca7ffcced8b7a7e7270a354d11700752c7f0ef04288' 
  AND token = 'W4MWpGMZ0KIutthKXSk2TN6tX9w4C4eigMBlvjIST0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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