SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f6069d89b78395598af1e423494df5425215065b9a3b5bfd71be36dbf5f4ee6' 
  AND token = 'Ehv3JcyVWizn+ewAckrMcoPQ4Khl4ahLgCqoelHVCy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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