SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8153120110634892416d33c55805ab5cf4b9abe96dff38d15a1b13ac7c7bd8bb' 
  AND token = 'j90a4aUWbPt+ABR+Juyt/VrT7vFUhPXXYnlrFkxPPL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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