SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '02c4e050fe4fb67a93404d3b0d33c7e939bb761ab630d71f3c7d809098e8dc22' 
  AND token = 'sgUwvWHBevtJJGTzrqFV4u0lu99fgSnjtPL40bPXqyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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