SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f795d1616a97c2007d3110557e8fdd09ae0edf2bcf81dfba685c8a47308daf1a' 
  AND token = 'XVD4fHaLdvExk8npLE6swdKJxNRq97D3VZZODzXenBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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