SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '825716017d69394871b40ccae3802ec274c27812f4a0bfde23294e96e3c08a4f' 
  AND token = 'Skn46qNMWLnNP03StPlAVGfpq/zOZAJabn50NLNE/F4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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