SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c430ff7bd84359b058c39058c08e348774fa3945543a92879891b9a1c58082' 
  AND token = 'VIxh/ti4yTYceOTxaaFLlmMmbADGRqiBIzgkCe/AGIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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