Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '42cbdf3a50b24f1d45cbf13c7173b646481bf71c1b4d5b1549259e8bd25e8892' 
  AND token = '1AswPc+AWBUXO7puLlAclH+yju2jJLAvF8qUc1tdMZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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