SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79f8305ca5b9cc70df991e1a1853bb4b02eabb5943276dd7f155fdba93ec891c' 
  AND token = 'gXaISMP/PG1bAzCuU8eGuQJWjol+IZitXxxE8LqYpe0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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