SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '148a82df79faa3b8f8cf6b57bc9ad3bc8d254629df2e73c7a38012a496940b33' 
  AND token = 'inBv8wNdzbEXMuxCNXq4JE6NRt/JXDj/1ldpGib4IjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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