SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e94fda1d5d3bac19985472e89f35bf69530ef37be78ae591ac59f3ad3dba6cd9' 
  AND token = 'GayGpPazhSZiI9Z/VwmJGSLqye88/OcrvNqoPqYJ0vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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