SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2a25e1bf9eeaa7aa9176be5dc88240b1b27750128b3fd72682abbb87340d336f' 
  AND token = 'KKh286aBBVaX3nC7njfvtMF+XjD6q1FRNkgXp1aIIwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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