SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'd35fcbf693a1df74a1d14739403d42524bb702efc1c9927baf4db31050994c22' 
  AND token = 'J2ZphByNUY6ot1U0+iU0PsOfbQj6G5gHSSQAXqp/DK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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