SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73796bc7af2ac113dbda7353493cb7c2b2e5b1233206d6dc7ee5c900bf0e2f86' 
  AND token = 'iyT9rn1hbuygNlGoBw6kWPVp8dibPZGhq1gwOX6t7Oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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