SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c8e609be4e7f20f56ee827b4a8931360e2d0fa38c12b8189ab018b27d491d8' 
  AND token = 'Hdc06F+2o4XmR7ODuL5JMSBJ/EsHo4jy+29Ukuu3skU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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