SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c45ce16cc66d6f6e294b23e8ecf57014f417d6447d19835099fcffaf90a9d4b9' 
  AND token = 'D5djmPSHgjEAA0lmWoqDmnewhHWCPEzKdwduJPikTWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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