SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1b25b5e249261058c15da7d443b7ed13d3d0d1b8fe6d1cc4c4cc2dd2355826db' 
  AND token = 'Sbsh5Qh8z0MEQBGVcXyhS+mMEM5o4CxUzC8X/bRruOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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