SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ae35ca47a5f4a48017aaa11188b3fbb9dc197bc18bbb36b2f365afe933f814a' 
  AND token = 'EBw6zC2K98FfRkIk0DdtmX/zRKt+1jRisKVSyLiLeVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}