SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0d3a57b4eb73f6fd19679c0dfbbdb0b10e08ececa0339938e350183a3f40164c' 
  AND token = 'Mza/5JlOT5vCb1KbPnnWdKnOb/P0PEg7BL0UfHb7lpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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