SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61adba0e3778e7bbefa9637b11237d6c2d7a8fdeecbdc15f54d1207a9206664f' 
  AND token = 'rdptr8cDi4Hd+XrGeLoSz/Vvfw/jWg1mhBlujjA+0mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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