SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '552389af446eb8dfb1785620749072e8b21a8a22448881856358ce07117fcd7d' 
  AND token = 'YEaGWItcfq70ifZvdGtIaMnU1Xs5woO5CEQvKwsdsXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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